eeyore

listen to the pronunciation of eeyore
English - English
An excessively negative or pessimistic person

You can't succeed as a Pollyanna or an Eeyore in the Product Management role — the glass is neither half full nor half empty, simply something that must eventually be washed.

a character in the Winnie the Pooh stories by A. A. Milne. He is a donkey (=an animal like a small horse with long ears) who usually feels sorry for himself
The donkey in A.A. Milnes book Winnie the Pooh and the Disney film of the same name